Why do staves have a different calculator than other weapons?

Well with the calculations removed on the staff units you now have a colorless mage which to me is kinda op.

So they can use up a slot, or refine, to have it calculated normally.

Just think how'd powerful staves could be without the refine, or B slot, being used for Wrathful Staff.

Kidding, I dunno why it's like that.

bc they hate staff users

Because having a mage that can also heal without drawbacks would make things too easy.

Or you can go with the lore and say "theyre not meant to hurt, theyre meant to heal"

I've only played 3 fire emblem games so l might be wrong here, but only reason l can think of is Staves always heal or buff, can't think of a staff doing damage. They usually class change into mages and are then able to deal damage that way, but again those are tomes that do damage, not the actual staff.